Many pipes or conduits, such as sewer laterals, phone ducts, or the like, are buried deep in the ground. Such pipes often develop leaks and it is expensive and time consuming to dig down from the surface and repair the leak. Attempts have been made to repair leaks by moving grout applying apparatus into the pipes through clean-out openings, but such devices have not possessed all the desired characteristics, namely, the ability to propel themselves efficiently along the pipe, especially around bends, to precisely seek out the leak, and to apply a repair substance such as grout in an efficient manner.